<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="./css/flex1.css">
    <title>Document</title>
    <style>
        

        .box:last-child {
            margin-right: 0;
        }
        
    </style>
</head>

<body>
    <div class="container">
        <div class="box b1">1</div>
        <div class="box b2">2</div>
        <div class="box b3">3</div>
        <div class="box b4">4</div>
        <div class="box b5">5</div>
        <div class="box b6">6</div>
        <div class="box b4">7</div>
        <div class="box b5">8</div>
        <div class="box b6">9</div>

    </div>
    
</body>

</html>